Highest temperature in Hong Kong on July 10?

Platform comparison

Market context

Hong Kong faces a hot, humid July 10 with forecasts pointing to a maximum near 33–34°C under typical subtropical summer conditions, yet the market currently assigns 0% probability to any YES outcome for the highest temperature event, creating a stark divergence from numerical consensus runs [1]. This zero-implied probability appears misaligned with the Hong Kong Observatory’s own outlook, which predicts a maximum of 32–33°C for Friday, 10 July, alongside hot conditions and a 65–90% chance of significant rain [9].

Historical July data frames this discrepancy: July and August are Hong Kong’s hottest months, with average highs around 32°C and daily ranges often reaching 32–33°C, while the 2026 seasonal forecast indicates normal to above-normal temperatures driven by an emerging strong El Niño and long-term climate warming [3][5]. The crowd’s 0% stance ignores that 33°C is the current frontrunner at 43% probability, with 32°C next at 31%, suggesting the market may be mispricing the baseline likelihood of a 33°C+ day [1].

Traders should monitor the Hong Kong Observatory’s “Daily Extract” for the finalized “Absolute Daily Max (deg. C)” once published, as settlement depends entirely on this official figure [1]. Key catalysts include real-time updates on significant rain probability and any sudden shifts in the El Niño intensity, which could push temperatures above the 33–34°C consensus range [3]. The market cannot resolve until the Observatory releases the confirmed data for 10 July 2026, making the timing of that publication the critical dependency for price discovery [1].

Sources: 1 · 2 · 3 · 4 · 5

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Is this market available outside the US?

Polymarket itself is geo-blocked in the US/UK/EU. Always check the legal status of prediction markets in your jurisdiction before trading.

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Prediction Today trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.